Commercial capon production in the U.S. is somewhat limited by
the labor involved in caponizing and the cost of feeding the birds to
attain a live weight of eight to ten pounds. The retail price for
capons Is considerably higher than for turkeys and for smaller female
chicken roasters or baking hens. It is possible that this price is
set partially by supply and demand, and that the cost of production
is not a major factor. The use of hormones to produce essentially
the same effect as caponizing may have Increasing Importance in the
capon industry.

This study was conducted to compare the performance, yield and
cooking characteristics of capons, roosters and hormone treated
male roasters.

EXPERIMENTAL PROCEDURE

Commercial-cross broiler males (from Arbor Acre females and
Peterson males) were placed on study at 8 weeks of age; prior to this
time they had received commercial-type starter and grower feeds. One
fourth had been surgically caponized at 51 weeks of age. A .21 cc
injection of Esmopall was given to one fourth of the birds at the
beginning of the study. All birds received ad libitum the diet shown
in Table 1 except that one fourth of the birds received, in addition,
L!pamone2 at the rate of 250 mg./kg. of feed from 8 weeks of age until
10 days prior to slaughter at 181 weeks of age. A total of 120 males
were used; one fourth of these were non-treated roosters. The 30
capons were randomly allocated to five floor pens (5' X 5H'); the
remaining 90 birds were randomly allocated to 15 identical pens prior
to initiation of the study. Birds were individually weighed at the
beginning and termination of the study.

Feed was withdrawn the evening prior to slaughter and the birds
were processed in a commercial plant using sub-scalding (140-143o F)
water and chilled in slush-ice overnight. The drained birds were then
weighed (without neck and giblets) and scored for the presence of breast

IEsmopal is the trade name for a paste product which, when injected
according to the manufacturer's suggestions, supplies 10 mgs. of estradiol
178 monopalmitate per dose; supplied by Mattox & Moore, Inc., Indianapolis
Indiana 46207.

2Lipamone is the trade name for a product containing 14% dienestrol
diacetate; supplied by the Schering Corporation, Bloomfield, N. J. 07018.

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blisters. If breast blisters were removed the birds were weighed
both before and after removal of the affected area.

Two birds from each treatment group were cooked In a 3500 house-
hold type oven to an end-point temperature of 1850 F as determined
by a Leeds and Northrup 24 point recording potentiometer using Minneapolis-
Honeywell Sabrecouples in the left breast of each bird. The birds
were cooked two at a time in V-shaped racks covered loosely with
aluminum foil. After cooling 30 minutes, weights were taken to
determine volatile, drip and total cooking losses. Samples (5/8"
square) of the pectoralis major were given to a taste panel for evaluation
of tenderness, juiciness and flavor and for the ability to distinguish
samples from the same and different birds.

A second study was initiated to evaluate the effects of caponizing
and of rearing conditions on breast blisters. Males of a Peterson male-
Peterson female cross were used. Half of the birds had been caponized
at 51 weeks of age; the study was initiated when the birds were 11
weeks of age. The same diet and pens were used as In the previous
study; four capons were allocated to each of four pens and roosters
were allocated likewise. Half of the pens of each treatment group
contained a box (2' X 2' X 8" high) under the water fountain. The
top of each box was covered with 1" X 2" welded wire. In half of the
pens this box was eliminated to determine whether or not the sharp
corners and the wire top added to the irritation of the breast
area and Increased breast blister incidence. Processing at 25
weeks of age was accomplished as in the previous study except that it
was done at the Poultry Unit rather than in a commercial plant.

RESULTS AND DISCUSSION

At the beginning of the first experiment the average weights for
each of the treatment groups were within a 100 gram range (Table 2).
The differences in initial weight were not significantly different.
At the termination of the study there was a range in average weights
of 339 grams and the group with the lowest Initial weight caponss)
had the highest final weight. The differences in final weight approached
significance at the .05 level of probability. The capons gained
significantly (P .05) more weight than any of the other groups. The
initial and final weights of all groups averaged 3.93 pounds and 8.81
pounds, respectively.

The birds in this study had an excessive number and severity of
breast blisters. Because of the great variation within groups the
differences attributed to treatment were not, however, significant.
The roosters had the lowest incidence and severity; the other groups
increased in the order of Lipamone, capons and Esmopal (Table 3).
Bird inactivity results in greater contact with the litter and would be
expected to Increase the Incidence of breast blisters. The roosters

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would be expected to have greater activity than the other groups and
thus have fewer blisters. Dressing percentages (Table 3) for the four
groups did not differ significantly either before or after removal of
breast blisters. The lowest dressing percentage was obtained with the
capons and this is likely due to a larger amount of abdominal fat
being removed during processing. The highest percentage was obtained with
Lipamone; this may be due to a higher fat distribution through the
muscle and skin.

The roosters had lower total cooking losses than the other three
groups (Table 4). A lower fat content of the roosters may have
affected the loss during cooking. The slight differences in cooking
times is attributed primarily to variations in placement of the
sabrecouples and possibility to differences in bird size.

No significant differences were noted in tenderness, juiciness
nor flavor (Table 5). However, the Lipamone treated birds had the
highest scores in two of these characteristics while those treated
with Esmopal had the lowest values in all three categories. The penel
was unable to distinguish between like and unlike samples.

It should be pointed out that the study was not favorable to any
group except the roosters. The birds treated with Esmopal and Lipamone
were beyond the age recommended by the manufacturers at the time the
study was terminated. The capons would have been favored by a longer
study.

The results of the second study are presented in Table 6. The
capons were slightly heavier (140 grams) than the roosters at the
beginning of the study and were significantly heavier (437 grams) at the
end of the study. The average weights of both groups was 5.25 pounds
and 9.71 pounds, respectively, at the beginning and end of the study.
There was little difference in dressing percentage nor breast blisters
between the capons and roosters. The capons and roosters in the pens
with the wire-covered boxes under the water fountains had a higher
breast blister incidence (P
boxes. This confirms earlier work that has shown that sharp objects
and wire floors increase breast blister incidence.

In this study the birds were older and heavier than those in the
first study and would have been expected to have a higher breast
blister incidence. The much lower incidence than in the first study
may be due to fact that a different strain of birds was used.